The physical property of nanocomposite material was influenced by dispersity of filler (CaCO3) in the polymer matrix (polypropylene). However quantification of the dispersity is hard to measurement. Here we try to find out an index of dispersity of nanocomposite in the proper regime, which close to the Einstein and Krieger-Dougherty Equation. The other method to confirm dispersity of composite we use SEM assisted by image analysis. Which analysis filler agglomerates area ratio of a micrograph of a composite. In this study, increasing the volume fraction of this study leading the ηr deviation from Einstein equation but still follow the Krieger-Dougherty’s curve which means the dispersion of high volume fraction is more difficult due to the aggregation of filler but in same volume fraction, changing the processing parameter such as twin screw speed significant improve the dispersity of nanocomposite.